Thermoplastics are the biggest constituent material group in polymer materials. This is because the mechanical properties of thermoplastics are preferable to other polymer types. Because of these mechanical properties, thermoplastic polymers find lots of applications areas in engineering. Here, we explain the general properties of thermoplastic polymers.
What Are The Mechanical Properties Of Thermoplastics?
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Thermoplastic materials have lower mechanical properties generally; lower stiffness, hardness, and greater ductility compared with ceramics and metals. These mechanical properties of thermoplastics depend on temperature.
As you know that thermoplastics can have crystalline or amorphous molecular forms. So mechanical properties of a thermoplastic material change according to its molecular form. If we consider the amorphous thermoplastics, they have a very critical property called ‘glass-transition temperature(Tg)’. Below the glass transition temperature, amorphous thermoplastics show solid characteristics. If amorphous thermoplastics are heated up around Tg, they will start to show rubbery characteristics. This rubbery characteristic of thermoplastics is called viscoelasticity. At the melting temperature of these thermoplastic materials, they show completely liquid characteristics called a viscous state.
But for crystalline thermoplastics, do not have any Tg that show rubbery characteristics. Crystalline thermoplastics are completely solid up to their melting temperature. After melting temperature, crystalline thermoplastics become completely liquid abruptly.
But there is a degree of crystallinity for mosy thermoplastic materials. So they can have both crystalline molecular structures and amorphous structures. So, these kinds of thermoplastics show mechanical and physical characteristics between complete crystalline and complete amorphous thermoplastic materials.
Also, the degree of polymerization and molecular weight of thermoplastics are very important parameters for properties. If the degree of polymerization and molecular weight increases for thermoplastics, they become more strong and hard mechanically. But their flowability was reduced. This makes it hard to process these high DP and MW of thermoplastics.
Mechanical properties of thermoplastics according to their different characteristics can be summarized as above. Do not forget to leave your comments and questions about the properties of thermoplastics below. Your precious feedbacks are very important for us.